大鲵α1-血红蛋白基因的生物信息学分析及组织表达研究

 从大鲵皮肤cDNA文库中分离获得大鲵α1 血红蛋白基因全长cDNA序列，生物信息学分析表明，大鲵α 血红蛋白基因全长cDNA序列为594 bp，开放阅读框共432 bp，编码144个氨基酸，编码的大鲵α1 血红蛋白推测的理论分子量为16048.3 u，等电点为6.44。氨基酸组成中酸性氨基酸11.9%，中性氨基酸69.9%，碱性氨基酸18.2%。结构分析表明，该蛋白没有信号肽，但在100~122个氨基酸处以及98~122个氨基酸处分别有由里向外、由外向里的跨膜螺旋区，二级结构以α 螺旋为主。氨基酸序进行同源性列比对表明与人、猕猴的亲缘关系最近，和牛蛙的亲缘关系最低只有35%。荧光定量PCR结果表明，α1 血红蛋白基因在肌肉中表达量最高，在胃中最低。

Bioinformatics Analysis and Tissue Expression of Alpha1 hemoglobin Gene from Andrias Davidianus

In this case, α1 Hb cDNA sequence was isolated and identified from skin cDNA library of Chinese giant salamander. The α1 Hb gene was 594 bp in the full length with the ORF 432 bp. Besides, 144 kinds of amino acids were encoded byα1 Hb gene, and the molecular weight was 16 048.3 u in general, isoelectric point was 6.44. In addition, the structure analysis of α1 Hb showed that the composition of amino acids were acidic amino acids 11.9%, neutral amino acids 69.9% and basic amino acid 18.2%. Structural analysis indicated that there was no signal peptide was existed in this protein but there was an outward transmembrane helical region from 100 th to 122 nd aa and also a inward transmembrane helical region from 98 th to 122 nd aa, whose secondary structure was mainly α helix.The three level structure ofα1 HB protein indicated the evolutional relationship was that Andrias davidianus was homologous to land animals, with Homo sapiens and Macaca mulatta homology of α1 HB was nearly 50%, and Rana catisbianna took the lowest homology (35%). Moreover, we were able to analyse the expression of α1 Hb gene mRNA in 7 tissues for Andrias davidianus by the data of qRT PCR, it was more expressed in muscle than the other six issues.